National Pollinator Week kicked off with a dark twist of irony Monday, when tens of thousands of bumblebees, honeybees, ladybugs and other insects were found dead or dying in a Target parking lot in Oregon. Now, early signs strongly suggest insecticides may be to blame.

Top image by Rich Hatfield | The Xerces Society

The death toll was highest for the bumblebees, and is thought to exceed 25,000 – a number that could represent a loss of more than 150 colonies. That estimate comes from Rich Hatfield, a conservation biologist with the Portland-based Xerces Society for Invertebrate Conservation, who went to investigate following several reports of dead and moribund bees carpeting the parking lot.

“They were literally falling out of the trees," said Hatfield, in reference to the European linden trees under which the bees were found to be clustered. "To our knowledge this is one of the largest documented bumblebee deaths in the Western U.S. It was heartbreaking to watch.”

Over the past decade, bee populations have been dropping, partly as a result of a disease called…
Read more Read more

The Xerces Society immediately contacted the Oregon Department of Agriculture (ODA), which launched an investigation into the death of the bees. It has since come to light that the linden trees were sprayed Saturday with an insecticide called "Safari" (marketed by Valent as "the fastest broad spectrum insecticide on the market") that may have been improperly applied.

“They made a huge mistake, but unfortunately this is not that uncommon,” said Xerces Executive Director Scott Hoffman Black in an interview with Oregon Public Broadcasting. “Evidently they didn’t follow the label instructions. This should not have been applied to the trees while they’re in bloom.”

More damning evidence: Safari's product label, available here, warns explicitly against its use in areas visited by bees:

This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area.

We've all heard that bee populations are dwindling. Far less clear, however, is what's…
Read more Read more

“I don’t think we’re there yet,” said ODA Communications Director Bruce Pokarney. “We’re looking at any other pesticide applications that might have taken place in the area that might have come into play. Until we get all that figured out, we stop short of saying this is the culprit or the likely culprit. It’s one of the possibilities we’re looking at. A very strong possibility.”

“It’s still going on,” said Black yesterday. “My staff is out there right now and there are still dead and dying bees.”